Method of arranging components of circuit board for optimal heat dissipation and circuit apparatus having components arranged by performing the method

ABSTRACT

A method of arranging a plurality of components of a circuit board for optimal heat dissipation and a circuit apparatus having a plurality of components arranged by performing the method are provided. The method includes arranging a predetermined number of the plurality of components in the order of size of the components in a heat dissipation area having a predetermined width on a virtual straight line connecting the air inlet unit and the air outlet unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.2008-58360, filed Jun. 20, 2008, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the present invention relate to an arrangement of componentsin an electronic circuit board, and in particular, to a method ofarranging components of a circuit board for optimal heat dissipation anda circuit apparatus having components arranged by performing the method.

2. Description of the Related Art

Electronic circuits, including switched mode power supplies (SMPS), haverecently become more miniaturized and integrated. In particular,components, such as power transistors that are mainly used in electroniccircuits, generate much heat while operating. If such electroniccircuits do not properly dissipate heat, many temperature-relatedproblems, such as stress, may occur. Such problems also result from afailure in the arrangement of electronic components in view of heatdissipation when electronic circuits are designed.

SUMMARY OF THE INVENTION

Aspects of the present invention provide a method of arrangingcomponents of a circuit board for optimal heat dissipation, therebyobtaining an optimal heat dissipation effect by appropriately arrangingelectronic components in an electronic circuit that dissipates muchheat, including a power circuit.

Aspects of the present invention also provide a circuit apparatus havingcomponents arranged by performing a method of arranging components of acircuit board for optimal heat dissipation.

Aspects of the present invention also provide a circuit board used in acircuit apparatus for optimal heat dissipation.

According to an aspect of the present invention, there is provided amethod of arranging a plurality of components of a circuit boardcomprising an air inlet unit and an air outlet unit for optimal heatdissipation, the method comprising: arranging a predetermined number ofthe plurality of components in a head dissipation area having apredetermined width on a virtual straight line connecting the air inletunit and the air outlet unit.

According to another aspect of the present invention, there is provideda circuit apparatus for implementing optimal heat dissipation, thecircuit apparatus comprising: a circuit board on which a predeterminednumber of a plurality of electronic components are mounted; an air inletunit providing a space for drawing air into the circuit board and thepredetermined number of the plurality of electronic components; an airoutlet unit providing a space for discharging air to the outside of thecircuit board; and the predetermined number of the plurality ofcomponents arranged in the circuit board, wherein the predeterminednumber of the plurality of components having a size larger than apredetermined size are arranged in the order of size of the componentsin a heat dissipation area having a predetermined width of the circuitboard in a virtual straight line connecting the air inlet unit and theair outlet unit.

According to another aspect of the present general inventive concept,there is provided a circuit board for implementing optimal heatdissipation, wherein the circuit board comprises a predetermined numberof a plurality of components among which larger components having a sizegreater than a predetermined size are arranged in the order of size ofthe components in a heat dissipation area having a predetermined widthin a virtual straight line connecting a point where air is taken in anda point where air is discharged.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee. These and/or other aspects and advantages of theinvention will become apparent and more readily appreciated from thefollowing description of the embodiments, taken in conjunction with theaccompanying drawings of which:

FIG. 1 is a schematic plan view of a circuit apparatus having componentsarranged by performing a method of arranging the components of a circuitboard for optimal heat dissipation according to an embodiment of thepresent invention;

FIG. 2 is a diagram for explaining a first aspect of arrangingcomponents for optimal heat dissipation according to an embodiment ofthe present invention;

FIG. 3 is a diagram for explaining a second aspect of arrangingcomponents for optimal heat dissipation according to an embodiment ofthe present invention;

FIG. 4A is an image showing air flow before a component-arrangementmethod is applied to a power circuit including a plurality of electroniccomponents according to an embodiment of the present invention;

FIG. 4B is an image showing air flow after the component-arrangementmethod is applied to the power circuit including the plurality ofelectronic components according to an embodiment of the presentinvention;

FIG. 5 is an image showing air resistance according to the size of acomponent having a rectangular shape according to an embodiment of thepresent invention;

FIG. 6 is an image showing air resistance according to the size of acomponent having a circular shape according to an embodiment of thepresent invention;

FIG. 7 is an image showing air resistance according to the distancebetween an air inlet unit and a component closest to the air inlet unitaccording to an embodiment of the present invention; and

FIG. 8 is an image showing air resistance according to two or morecomponents that are arranged in parallel to each other according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures.

FIG. 1 is a schematic plan view of a circuit apparatus having componentsarranged by performing a method of arranging the components of a circuitboard 100 for optimal heat dissipation according to an embodiment of thepresent invention.

Referring to FIG. 1, the circuit apparatus comprises the circuit board100, an air inlet unit 110, an air outlet unit 120, and a plurality ofcomponents 142, 144, 146, and 148.

The circuit board 100, in which electronic components having varioussizes and constituting an electronic circuit are arranged, is generallya printed circuit board (PCB).

The air inlet unit 110 is a sealed space adjoining the circuit board 100and the components 142, 144, 146, and 148, which are mounted on thecircuit board 100, so as to take in air, and has a circular orrectangular shape, however the present invention is not limited thereto.The air outlet unit 120 is a sealed space adjoining the circuit board100 and the components 142, 144, 146, and 148, which are mounted on thecircuit board 100, so as to discharge air. The air outlet unit 120 has acircular or rectangular shape, however the present invention is notlimited thereto.

In the circuit apparatus of the present embodiment, the relativelylarger components 142, 144, 146, and 148 are located in a heatdissipation area 140 having a predetermined width and arranged in astraight line connecting the air inlet unit 110 and the air outlet unit120. The geometric centers of the components 142, 144, 146, and 148arranged in the heat dissipation area 140 may be located in an areawithin 1.5 times the dimension of the components 142, 144, 146, and 148from a center axis that is a virtual straight line from the air inletunit 110 to the air outlet unit 120. For example, if the dimension ofeach of the components 142, 144, 146, and 148 is 20 mm, the centers ofeach of the components 142, 144, 146, and 148 may be located within 30mm from the center axis. For example, the dimension of the circularcomponent 144 is the diameter of the circular component 144, and thedimension of the rectangular component is the length of the larger sideof the two sides of the rectangular components.

The number or shapes of the components 142, 144, 146, and 148 arrangedin the heat dissipation area 140 are not limited by the descriptionsgiven in the exemplary embodiments. The components 142, 144, 146, and148 may be spaced apart from the air inlet unit 110 or the air outletunit 120 by a distance more than the dimensions of the components 142,144, 146, and 148. For example, if the dimensions of the components 142,144, 146, and 148 are 10 mm, the components 142, 144, 146, and 148 maybe spaced apart from the air inlet unit 110 or the air outlet unit 120by more than 10 mm. The components 142, 144, 146, and 148 arranged inthe heat dissipation area 140 are spaced apart from the air inlet unit110 or the air outlet unit 120 by more than 5 times an inverse number ofthe size of the air inlet unit 110 or the air outlet unit 120. Forexample, if the size of the air inlet unit 110 is 2 cm, the components142, 144, 146, and 148 may be spaced apart from the air inlet unit 110by more than 2.5 cm, that is, 5 times ½ cm. Hereinafter, for the sake ofclarity and convenience, referring to FIG. 1, a direction parallel tothat of the virtual straight line connecting the air inlet unit and theair outlet unit is referred to as a first direction, and a directionvertical to the first direction is referred to as a second direction.The size of the air inlet unit or the air outlet unit is the length(second direction) of the air inlet unit or air outlet unit into whichthe air inlets or outlets. For example, a rectangular air inlet unit 100having a size of 2 cm may have a length of 2 cm (second direction) ofthe air inlet unit 110 into which the air inlets.

If the components 142, 144, 146, and 148 arranged in the heatdissipation area 140 have rectangular cross-sections, the lengths of thecomponents 142, 144, 146, and 148 are more than ¼ the size of the airinlet unit 110 or the air outlet unit 120 along a horizontal axis withregard to the straight line from the air inlet unit 110 to the airoutlet unit 120. If the components 142, 144, 146, and 148 arranged inthe heat dissipation area 140 have circular cross-sections, diameters ofthe components 142, 144, 146, and 148 may be more than ¼ the size of theair inlet unit 110 or the air outlet unit 120.

If the components 142, 144, 146, and 148 are heat sinks, the heat sinksmay be arranged in the heat dissipation area 140 so that edge directionsof the heat sinks are identical to convectional current directionsthereof.

In more detail, the components 142, 144, 146, and 148 of the presentembodiment are arranged according to the following two aspects discussedbelow.

Referring to FIG. 2, with regard to a first aspect, components greaterthan a predetermined size, such as a line filter 242, a condenser 244, atransformer 246, and an output capacitor 248, are arranged in a heatdissipation area 240 of a circuit board 200 with regard to a center axisthat is a virtual straight line connecting an air inlet unit 210 and anair outlet unit 220. A distance between the line filter 242, thecondenser 244, the transformer 246, and the output capacitor 248 and thecenter axis may be within 1.5 times the size of each of the line filter242, the condenser 244, the transformer 246, and the output capacitor248. The centers of the line filter 242, the condenser 244, thetransformer 246, and the output capacitor 248 may be located within thedistance. For example, if the size of each of the line filter 242, thecondenser 244, the transformer 246, and the output capacitor 248 is 20mm, the centers of the line filter 242, the condenser 244, thetransformer 246, and the output capacitor 248 may be located within 30mm from the center axis. The components, which are the line filter 242,the condenser 244, the transformer 246, and the output capacitor 248,are arranged in the heat dissipation area 240 and are spaced apart fromthe air inlet unit 210 or the air outlet unit 220 by more than the sizeof the components. In more detail, if the size of one of the line filter242, the condenser 244, the transformer 246, and the output capacitor248 that is the closest to the air inlet unit 210 or the air outlet unit220 is 10 mm, the closest one is spaced apart from the air inlet unit210 or the air outlet unit 220 by more than 10 mm. The line filter 242,the condenser 244, the transformer 246, and the output capacitor 248arranged in the heat dissipation area 240 may be spaced apart from theair inlet unit 210 or the air outlet unit 220 by more than 5 times aninverse number of the size of the air inlet unit 210 or the air outletunit 220. For example, if the size of the air inlet unit 210 is 2 cm,the line filter 242, the condenser 244, the transformer 246, and theoutput capacitor 248 may be spaced apart from the air inlet unit 210 bymore than 2.5 cm, that is, 5 times ½ cm.

In this case, convectional air currents are less influenced by eachcomponent and uniformly influence each component of the circuitapparatus. The circuit board 200 must be spaced apart from the air inletunit 210 by more than a predetermined space so that air can be properlytaken in.

Referring to FIG. 3, with regard to a second condition, an electroniccomponent having a difference between a horizontal length l and avertical length w is arranged on a circuit board so that the shorter oneof the horizontal length l and the vertical length w is arranged withregard to a convectional current direction. If the electronic componentis a heat sink, the convection current direction in which air flows isarranged to be an edge direction of the heat sink. Therefore, a smallamount of air resistance is applied in a direction perpendicular to theshorter length of the electronic component and the edge direction of theheat sink so that air convection efficiently takes place throughout thecircuit apparatus. Air convection properly takes place owing to thefirst and second aspects, thereby efficiently dissipating heat of theelectronic components.

FIG. 4A is an image showing air flow before a component-arrangementmethod is applied to a power circuit having a plurality of electroniccomponents according to an embodiment of the present invention. FIG. 4Bis an image showing air flow after the component-arrangement method isapplied to the power circuit including the plurality of electroniccomponents according to an embodiment of the present invention.

FIG. 5 is an image showing air resistance according to the size of acomponent having a rectangular shape according to an embodiment of thepresent invention. Referring to FIG. 5, the air resistance occurs withregard to the amount of air flow around the component having therectangular shape having a horizontal axis greater than 20 mm.Therefore, since the air resistance causes air flow to be restricted atthe bottom of the component, it is necessary to arrange componentshaving a horizontal axis greater than 15 mm.

FIG. 6 is an image showing air resistance according to the size of acomponent having a circular shape according to an embodiment of thepresent invention. Referring to FIG. 6, the air resistance occurs withregard to the amount of air flow around the component of the circularshape having a radius greater than 15 mm. Therefore, it is necessary toarrange components having a radius greater than 10 mm.

FIG. 7 is an image showing air resistance according to the distancebetween an air inlet unit and a component closest to the air inlet unitaccording to an embodiment of the present invention. Referring to FIG.7, since the air resistance occurs when the component is spaced apartfrom the air inlet unit by less than 10 mm, the component needs to bespaced apart from the air inlet unit by more than 15 mm.

FIG. 8 is an image showing air resistance according to two or morecomponents that are arranged in parallel to each other according to anembodiment of the present invention. Referring to FIG. 8, if thedistance between the two or more components is more than 20 mm, aconvection error partially occurs. Thus, it is necessary to arrange thetwo or more components within 15 mm from a center horizontal distance ina vertical axis of an air inlet unit and an air outlet unit.

The circuit apparatus of the present embodiment can be useful for apower circuit apparatus such as a switched mode power supply (SMPS).

A method of arranging components of a circuit board for optimal heatdissipation and a circuit apparatus having components arranged byperforming the method of the present invention can efficiently dissipateheat generated by an electronic circuit, such as a power circuit, andcan increase the reliability of an electronic circuit system and thelifespan of components.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

What is claimed is:
 1. A method of arranging a plurality of componentsof a circuit board having an air inlet unit and an air outlet unit foroptimal heat dissipation, the method comprising: arranging apredetermined number of the plurality of components in a heatdissipation area having a predetermined width on a virtual straight lineconnecting the air inlet unit and the air outlet unit, wherein thecomponents arranged in the heat dissipation area are relatively largerthan the components located outside of the heat dissipation area on thecircuit board, wherein the plurality of components arranged in the heatdissipation area are spaced apart from the air inlet unit or the airoutlet unit by more than 5 times an inverse number of a size of one ofthe air inlet unit or the air outlet unit, and wherein the size of oneof the air inlet unit or the air outlet unit is a length of the airinlet unit or the air outlet unit into which the air inlets or outlets,measured in centimeters.
 2. The method of claim 1, wherein the pluralityof components arranged in the heat dissipation area are spaced apartfrom each other by a gap greater than a dimension of one of theplurality of components that is the closest to the air inlet unit or theair outlet unit.
 3. The method of claim 1, wherein each of thecomponents of the plurality of components includes a center, the centerof each component being arranged in the heat dissipation area so thatthe center is located within 1.5 times a dimension of the component in awidth direction of the heat dissipation area from a center axis of theheat dissipation area.
 4. The method of claim 1, wherein the pluralityof components arranged in the heat dissipation area have rectangular orcircular cross-sections, wherein lengths of the plurality of componentsarranged in the heat dissipation area having the rectangularcross-sections are more than ¼ a size of one of the air inlet unit orthe air outlet unit on a horizontal axis with regard to the virtualstraight line, wherein diameters of the plurality of components arrangedin the heat dissipation area having the circular cross-sections are morethan ¼ a size of one of the air inlet unit or the air outlet unit. 5.The method of claim 1, wherein the plurality of components comprise heatsinks, wherein the heat sinks are arranged in the heat dissipation areaso that an edge direction is identical to a convectional currentdirection.
 6. A circuit apparatus, the circuit apparatus comprising: acircuit board on which a predetermined number of a plurality ofelectronic components are mounted; an air inlet unit providing a spacefor drawing air over the circuit board and the predetermined number ofthe plurality of electronic components; an air outlet unit providing aspace for discharging air to the outside of the circuit board; and thepredetermined number of the plurality of components arranged on thecircuit board, wherein the predetermined number of the plurality ofcomponents are arranged in a heat dissipation area having apredetermined width of the circuit board in a virtual straight lineconnecting the air inlet unit and the air outlet unit, wherein thecomponents arranged in the heat dissipation area are larger than thecomponents located outside of the heat dissipation area on the circuitboard, wherein the plurality of components arranged in the heatdissipation area are spaced apart from the air inlet unit or the airoutlet unit by more than 5 times an inverse number of a size of one ofthe air inlet unit or the air outlet unit, and wherein the size of oneof the air inlet unit or the air outlet unit is a length of the airinlet unit or the air outlet unit into which the air inlets or outlets,measured in centimeters.
 7. The circuit apparatus of claim 6, whereinthe plurality of components arranged in the heat dissipation area arespaced apart from each other by a gap greater than a dimension of one ofthe plurality of components that is the closest to the air inlet unit orthe air outlet unit.
 8. The circuit apparatus of claim 6, wherein eachof the components of the plurality of components includes a center, thecenter of each component being arranged in the heat dissipation area sothat the center is located within 1.5 times a dimension of the componentin a width direction of the heat dissipation area from a center axis ofthe heat dissipation area.
 9. The circuit apparatus of claim 6, whereinthe plurality of components arranged in the heat dissipation area haverectangular or circular cross-sections, wherein lengths of the pluralityof components arranged in the heat dissipation area having therectangular cross-sections are more than ¼ a size of one of the airinlet unit or the air outlet unit on a horizontal axis with regard tothe virtual straight line, wherein diameters of the plurality ofcomponents arranged in the heat dissipation area having the circularcross-sections are more than ¼ a size of one of the air inlet unit orthe air outlet unit.
 10. The circuit apparatus of claim 6, wherein theplurality of components comprise heat sinks, wherein the heat sinks arearranged in the heat dissipation area so that an edge direction isidentical to a convectional current direction.
 11. A method of forming aheat dissipation area of a circuit board having an air inlet unit and anair outlet unit, the method comprising: determining a location of avirtual straight line between the air inlet unit and the air outletunit; and disposing a plurality of components having a size greater thana predetermined size along the virtual straight line to form the heatdissipation area, wherein one of the plurality of components disposedclosest to the air inlet unit or one of the plurality of componentsdisposed closest to the air outlet unit are respectively spaced apartfrom the air inlet unit or the air outlet unit by more than 5 times aninverse number of the respective size of one of the air inlet unit orthe air outlet unit, and wherein the size of one of the air inlet unitor the air outlet unit is a length of the air inlet unit or the airoutlet unit into which the air inlets or outlets, measured incentimeters.
 12. The method of claim 11, wherein the plurality ofcomponents disposed along the virtual straight line are spaced apartfrom each other by a gap greater than a dimension of one of theplurality of components disposed closest to the air inlet unit or one ofthe plurality of components disposed closest to the air outlet unit. 13.The method of claim 11, wherein each of the components of the pluralityof components includes a center, the center of each component beingdisposed in the heat dissipation area so that the center is locatedwithin 1.5 times the dimension of the plurality of components in a widthdirection of the heat dissipation area from a center axis of the heatdissipation area.
 14. The method of claim 11, wherein the plurality ofcomponents arranged in the heat dissipation area have rectangular orcircular cross-sections, wherein the lengths of the plurality ofcomponents arranged in the heat dissipation area having the rectangularcross-sections are more than ¼ the size of the air inlet unit or the airoutlet unit on a horizontal axis with regard to the virtual straightline, wherein the diameters of the plurality of components arranged inthe heat dissipation area having the circular cross-sections are morethan ¼ the size of the air inlet unit or the air outlet unit.
 15. Themethod of claim 11, wherein the plurality of components comprise heatsinks, wherein the heat sinks are arranged in the heat dissipation areaso that an edge direction is identical to a conventional currentdirection.
 16. A circuit apparatus including a heat dissipation area,the circuit apparatus comprising: a circuit board on which a pluralityof electronic components are mounted; an air inlet unit for drawing airto the circuit board; an air outlet unit for discharging air away fromthe circuit board; and the heat dissipation area formed along a virtualstraight line located between the air inlet unit and the air outletunit, wherein the plurality of components having a size greater than apredetermined size are disposed so as to intersect the virtual straightline, the plurality of components arranged in the heat dissipation areaare spaced apart from the air inlet unit or the air outlet unit by morethan 5 times an inverse number of a size of one of the air inlet unit orthe air outlet unit, and the size of one of the air inlet unit or theair outlet unit is a length of the air inlet unit or the air outlet unitinto which the air inlets or outlets, measured in centimeters.
 17. Thecircuit apparatus of claim 16, wherein the plurality of componentsarranged in the heat dissipation area are spaced apart from each otherby a gap greater than a dimension of one of the plurality of componentsthat is the closest to the air inlet unit or the air outlet unit. 18.The circuit apparatus of claim 16, wherein each of the components of theplurality of components includes a center, the center of each componentbeing arranged in the heat dissipation area so that the center islocated within 1.5 times a dimension of the components in a widthdirection of the heat dissipation area from a center axis of the heatdissipation area.
 19. The circuit apparatus of claim 16, wherein theplurality of components arranged in the heat dissipation area haverectangular or circular cross-sections, wherein lengths of the pluralityof components arranged in the heat dissipation area having therectangular cross-sections are more than ¼ a size of one of the airinlet unit or the air outlet unit on a horizontal axis with regard tothe virtual straight line, wherein diameters of the plurality ofcomponents arranged in the heat dissipation area having the circularcross-sections are more than ¼ a size of one of the air inlet unit orthe air outlet unit.
 20. The circuit apparatus of claim 16, wherein theplurality of components comprise heat sinks, wherein the heat sinks arearranged in the heat dissipation area so that an edge direction isidentical to a convectional current direction.